Wireless communication devices, network connection nodes, systems and methods

ABSTRACT

A wireless communication device comprising circuitry that is configured to measure, in an idle mode, only macro cells, and to start the measurement of one or more indirect network connection nodes in accordance with the wireless communication device turning into a connected mode.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. application Ser. No.16/091,318, filed Oct. 4, 2018, which is a National Stage Application ofPCT International Application No. PCT/EP2017/058250, filed Apr. 6, 2017,which claims priority to European Patent Application No. 16164099.0,filed Apr. 6, 2016, the content of each is hereby incorporated byreference into this application.

TECHNICAL FIELD

The present disclosure generally pertains to the field of wirelesstelecommunications, in particular to wireless communication devices,network connection nodes, communication systems and methods for suchcommunication systems.

TECHNICAL BACKGROUND

Several generations of mobile telecommunications systems are known, e.g.the third generation (“3G”) which is also known as UMTS standard, thefourth generation (“4G”), known as the LTE standard, and the currentfifth generation (“5G”), which is still under development.

LTE is standardized under the control of 3GPP (“3rd GenerationPartnership Project”) and there exists a successor LTE-A (LTE Advanced)which allowing higher data rates as the basis LTE and which is alsostandardized under the control of 3GPP.

The 5G system will be based on LTE or LET-A, respectively, so thatspecific requirements of the 5G technologies will be based on technologythat is already defined in the LTE and LTE-A standard documentation.

5G technologies will allow a concept of a so called “virtual cells”,“local cells”, or the like. In this concept a cell may be served by auser equipment (“UE”). In short the UE may work dynamically as anintermediate node for establishing an indirect network connectionbetween other UEs in the vicinity of the virtual cell or local cell andthe network, and/or as an intermediate node between UEs. A function ofthe intermediate node on the UE may be carried out by “virtualization”.A virtual cell or local cell may communicate with UEs in unlicensed,shared licensed or licensed bands, and it backhands to networkpreferably in licensed bands.

A logical separation between control plane and user plane has been donein accordance with introduction of the IP Multimedia System (IMS) forLTE, and a physical separation between control plane and user plane hasbeen proposed as a possible solution for 5G. Since requirements for thecontrol plane should be basically robustness and wide coverage so as tomaintain the service continuity, a macro base station should provide alink of the control plane. On the other hand a key performance of theuser plane is the efficient spectrum usage in order to improve the cellcapacity. However, since the requirements of the user plane are highlydepending on specific use case or UE capability/category, a variety oftypes of reception/transmission or routing methods are consideredaccording to the respective use case or UE capability/category takinginto account a concept for 5G such as “network slicing”.

Still further, Radio Resource Control (RRC) is categorized into thecontrol plane and the RRC management should be performed in accordancewith methods to provide the control plane in the context of a physicalseparation between control plane and user plane in 5G.

In view of this it is generally desirable to improve known wirelesscommunication methods, systems, devices and network nodes.

SUMMARY

According to a first aspect the disclosure provides a wirelesscommunication device comprising circuitry that is configured to measure,in an idle mode, only macro cells, and to start the measurement of oneor more indirect network connection nodes in accordance with thewireless communication device turning into a connected mode.

According to a further aspect the disclosure provides a methodcomprising: sending, by a macro cell, a configuration message to awireless communication device, the configuration message comprising aconfiguration of measurement reporting; and performing, by the wirelesscommunication device, a measurement of one or more indirect networkconnection nodes for providing a user plane as well as macro cells,according to configured setup of measurement reporting.

According to a still further aspect the disclosure provides a methodcomprising: sending, by a UE, an RRC Connection Request message to aneNB; sending, by the eNB, an RRC Connection Setup message to the UE, theRRC Connection Setup message comprising a configuration of UEmeasurement reporting; sending, by the UE, a RRC Connection SetupComplete message to the eNB; starting, by the eNB, the provision ofcontrol plane to the UE; performing, by the UE, a measurement of virtualcells for user plane as well as macro cells, according to configuredsetup of measurement reporting; sending, by the UE, a respectivemeasurement report to eNB when an event of reporting a measurement istriggered; requesting, by the eNB, a virtual cell to provide the UE witha user plane; and starting, by the virtual cell, to provide the UE witha user plane.

According to a still further aspect the disclosure provides an indirectnetwork connection node comprising circuitry configured to provide auser plane and/or a control plane to a wireless communication device.

According to a still further aspect the disclosure provides a systemcomprising a wireless communication device; at least one macro cell, themacro cell being configured to provide a control plane to the wirelesscommunication device; and at least one indirect network connection node,the indirect network connection node being configured to provide a userplane and/or a control plane to the wireless communication device.

Further aspects are set forth in the dependent claims, the followingdescription and the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments are explained by way of example with respect to theaccompanying drawings, in which:

FIG. 1 schematically discloses an example of a UE operating in idlemode;

FIG. 2 schematically depicts an example of a UE operating in initialconnected mode;

FIG. 3 schematically depicts an example of a UE operating in operationalconnected mode;

FIG. 4 shows an embodiment of a RRC Connection Setup message;

FIG. 5 shows “Measurement Objects” in more detail;

FIG. 6 schematically shows an example of a procedure to activate theprovision of user plane by a virtual cell;

FIG. 7 schematically shows an example of a procedure to release theprovision of control plane by an eNB and user plane by a virtual cell;

FIG. 8 shows an exemplary embodiment in which a UE is provided with twocontrol planes; and

FIG. 9 schematically describes an embodiment of an electronic devicethat can be used to implement a wireless communication device that canact as UE in a telecommunication network.

DETAILED DESCRIPTION OF EMBODIMENTS

Before a detailed description of the embodiments under reference of theFigures is given, some general explanations are made.

The embodiments disclose a wireless communication device comprisingcircuitry, that is configured to measure, in an idle mode, only macrocells, and to start the measurement of one or more indirect networkconnection nodes in accordance with the wireless communication deviceturning into a connected mode.

The wireless communication device may for example be a user equipment(UE) such as a mobile phone, a computer, tablet, tablet personalcomputer, or the like.

Macro cells may for example be defined by base stations that have adirect link to the network, e.g. a eNB, or the like.

An indirect network connection node may be any network connection nodethat is indirectly connected to the network via another base station,e.g. via an eNB.

Indirect network connection nodes may for example comprise high densewireless small cells, e.g. a virtual cell, local cell, or the like.

A virtual cell/local cell may for example be a user equipment (UE), e.g.a mobile phone, a computer, tablet, tablet personal computer or thelike, including a mobile communication interface, or any other devicewhich is able to perform a mobile telecommunication via, for example,LTE(-A), such as a hot spot device with a mobile communicationinterface.

The wireless communication device (acting as UE in a network) mayinitially be in the idle mode, where it measures only macro cells. Theidle mode may for example be an RRC Idle mode, or the like. Themeasurement of (macro) cells relates to mobility management. By means ofthe measurements of macro cells, the wireless communication device mayselect a base station (e.g. an eNB) among candidate base stations whichare configured prior to the establishment of a connection to thenetwork. In general, the aim of mobility management is to track where UEis located, allowing calls, SMS and other mobile phone services to bedelivered to them. For example, in the RRC Idle mode mobility managementcan be implemented through the cell selection/reselection process. Thewireless communication device may autonomously perform cellreselections, i.e. it may change from cell to cell whenever required bysignal conditions.

In order to start data or voice transmission, the wireless communicationdevice turns from idle mode into connected mode. In the connected mode,the wireless communication device is connected with a macro cell whichprovides a control plane to the wireless electronic device. Theconnected mode may for example be an RRC Connected mode. The connectedmode must not necessarily be an operational connected mode (includingthe provision of a user plane). It may also be an initial connectedstate such as a RRC Initial Connected mode, in which only a controlplane is provided to the wireless communication device by a macro cell(e.g. by an eNB).

The embodiments also disclose a wireless communication device in whichthe circuitry is configured to receive/transmit a control plane from/toa macro cell and a user plane from/to an indirect network connectionnode.

The embodiments described in more detail below disclose an RRCmanagement under network operation with separated control plane and userplane utilizing an indirect network connection node such as a high densewireless small cell, e.g. a virtual cell/local cell. According to theembodiments, the wireless communication device may exchange data with anetwork via the user plane provided by the indirect network connectionnode (e.g. virtual cell/local cell). At the user plane side, anapplication may create data packets that are processed by protocols suchas TCP, UDP and IP, while in the control plane, the radio resourcecontrol (RRC) protocol writes signaling messages that are exchangedbetween a base station (eNB) and the wireless communication device (UE).A control plane may handle radio-specific functionality which depends onthe state of the UE, e.g. the RRC states: idle or connected. A userplane protocol stack between the eNB and UE may for example comprise thesub-layers PDCP (Packet Data Convergence Protocol), RLC (radio LinkControl), and Medium Access Control (MAC).

The providing of a user plane by the indirect network connection node tothe wireless communication device may reduce overhead of measurement forselection of base stations under operation with separation of controlplane and user plane.

The embodiments also disclose a wireless communication device in whichthe circuitry is configured to trigger a measurement of virtualcells/local cells in addition to that of macro cells in accordance withan RRC connection establishment.

The RRC connection establishment procedure is well known as theprocedure which is used to make the transition from RRC Idle mode to RRCConnected mode. A UE makes the transition to RRC Connected mode beforetransferring any application data, or completing any signalingprocedures.

The embodiments also disclose a wireless communication device in whichthe circuitry is further configured to receive a configuration messageand to perform measurement reporting as defined by the configurationmessage.

This configuration message may for example be an RRC Connection Setupmessage. A measurement reporting that is configured by a RRC ConnectionSetup message may for example include intra-frequency/inter-frequencymeasurement for attaching a user plane served by a virtual cell/localcell.

The configuration of the measurement may for example be defined by“Measurement Objects”, “Reporting Configurations”, “MeasurementIdentities”, “Quantity Configurations” and “Measurement Gaps” identifiedin a RRC Connection Setup message.

The embodiments also disclose a wireless communication device in whichthe configuration message defines measurement objects, the measurementobjects including intra-frequency measurement objects/inter-frequencymeasurement objects which specify individual cells to measure. A list ofmeasurement objects that specifies individual cells that are to bemeasured by a UE may be regarded as a whitelist or Neighbour Cell Listof measurement objects. The whitelist/Neighbour Cell List may inparticular comprise indirect network connection nodes such as virtualcells/local cells in addition to macro cells. Individual cells may forexample be referred to by their Physical layer Cell Identities (PCI) inconventional manner.

The embodiments also disclose a wireless communication device in whichthe configuration message defines individual cells that are to beexcluded from measurements. A list of measurement objects that specifiesindividual cells that are to be excluded from measurements by thewireless communication device (UE) may be regarded as a blacklist ofmeasurement objects. The black list may in particular comprise indirectnetwork connection nodes such as virtual cells/local cells in additionto macro cells. As in the case of the whitelist, individual cells mayfor example be referred to by their Physical layer Cell Identities (PCI)in conventional manner.

The embodiments also disclose a wireless communication device in whichthe configuration message defines one or more macro cells for aprovision of control plane and one or more indirect network connectionnodes for a provision of a user plane. According to this embodiment, thewireless communication device may measure further the indirect networkconnection node(s) configured by a RRC Connection Reconfigurationmessage in accordance with RRC connection establishment procedureperformed via control plane served by macro-cell, during only connectedmode. That is to say, the wireless communication device can measure onlythe macro cell(s) during idle mode and do the indirect networkconnection node(s) such as virtual cell(s)/local cell(s) as well as themacro cell(s) during connected mode. According to yet an alternativeembodiment a whitelist/Neighbour Cell List may be categorized into listsfor idle mode and connected mode.

Still alternatively a whitelist/Neighbour Cell List may be categorizedinto lists for control plane and user plane.

These lists related to Intra-Frequency may be provided via SIB(SystemInformation Block) 4 and those related to Inter-Frequency are providedvia SIBS.

According to a further alternative embodiment anotherwhitelist/Neighbour Cell List for connected mode or user plane mayinclude virtual cells/local cells as candidate cells for measurement, asdifferent from macro cells which are included in a whitelist/NeighbourCell List for control plane or idle mode. This anotherwhitelist/Neighbour Cell List can be provided via SIB4 or SIB5 dependingon Intra-Frequency or Inter-Frequency, or it may be provided via somedifferent SIB(s) in accordance with a RRC Connection Setup, RRCConnection Reconfiguration and RRC Connection Reestablishment messages.Here e.g. the RRC Connection Setup message can be sent in an RRCconnection establishment procedure which allows a UE to make thetransition from RRC Idle mode to RRC Connected mode. Furthermore whetherthe said another whitelist/Neighbour Cell List is provided, may dependon what kind of applications the UE initiates, what kind of UEcapabilities/categories the UE has or what kind of mobility states theUE is (e.g. with pedestrian, in a vehicle, in a train or the like), inaccordance with the RRC connection establishment procedure.

Furthermore, indirect network connection nodes such as virtualcells/local cells may operate with different Radio Access Technologies(RAT), in particular with different Radio Access Technologies than macrocells. In such cases individual lists (e.g. blacklists andwhitelists/Neighbour Cell Lists) may be foreseen for each Radio AccessTechnology. For example, the “Measurement Objects” may includeindividual whitelists/Neighbour Cell Lists and/or blacklists for virtualcells/local cells which operate with a different Radio AccessTechnologies (RAT), as well as an individual whitelist/Neighbour CellList and blacklist for virtual cells/local cells operating with the sameRAT as a macro-cell.

The embodiments also disclose a wireless communication device in whichthe circuitry is further configured to manage connection states incooperation with the network, wherein connection states for a controlplane include an idle and/or a connected state, and the connectionstates for the user plane include at a least a connected state. This mayfor example be achieved by a separate connection state management of theremote UE to control plane or user plane, respectively.

The embodiments also disclose a wireless communication device in whichthe circuitry is further configured to configure settings related tomeasurement reporting based on a classification of cell identification.The cell classification may for example be based on at least one of asize of cell coverage, a maximum transmission power, a number ofequipped antenna, an operating frequency band and bandwidth.

The embodiments also disclose a wireless communication device in whichthe circuitry is further configured to receive/transmit a control planeprovided by an indirect network connection node and a user plane that isprovided by the indirect network connection node.

For example, a connection to an indirect network connection node may bedivided into a connection for control signaling (control plane) and aconnection for data communication (user plane) in logical or physicalmanner.

The embodiments also disclose a wireless communication device in whichthe circuitry is further configured to receive/transmit a first controlplane provided by an indirect network connection node and a secondcontrol plane that is provided by a macro cell.

For example, an indirect network connection node may configure thesettings of measurement reporting of the indirect network connectionnode in accordance with establishment of the connection of the wirelesscommunication device to the indirect network connection node, and ameasurement report may be sent on the link between the wirelesscommunication device and the indirect network connection node.

The embodiments also disclose a wireless communication device in whichthe control plane is provided by a macro cell (e.g. an eNB) and in whichthe control plane handles controls related to mobility management, thescheduling assignment, and/or the measurement reporting for both themacro cell and the indirect network connection node.

The embodiments also disclose a wireless communication device comprisingcircuitry configured to manage event triggers for independentlyreporting measurement results to the macro cell and/or to the indirectnetwork connection node.

For example event driven reports or periodic reports for an eNB can beconfigured by an RRC Connection Setup message in accordance with the RRCConnection Setup procedure and event driven reports or periodic reportsfor the virtual cell can be configured by an RRCConnectionReconfiguration message in accordance with the RRCConnectionReconfiguration procedure respectively.

According to another embodiment, the measurement of each link betweeneNB and UE or between a virtual cell/local cell and the UE is handled bythe eNB or the virtual cell/local cell independently, each having arespective control plane over each link. Even if independentconfiguration of measurement reporting is performed, since the eNBhandles both decision of handover of eNB itself and attach/detach of theconnection between the virtual cell/local cell and UE, the measurementreport on the link between virtual cell/local cell and UE may be sent tothe eNB via the virtual cell/local cell using its backhaul link.

The embodiments also disclose a wireless communication device in whichthe circuitry is further configured to perform a HARQ function withinthe localized area served by the indirect network connection node.

The embodiments also disclose a wireless communication device in whichthe circuitry is further configured to manage a HARQ on the link betweenthe indirect network connection node and the wireless communicationdevice by a control plane provided by the indirect network connectionnode so as to perform re-transmission according to HARQ process withinthe localized area.

The wireless communication device may then confirm the secondconfiguration message by sending a confirmation message such as an RRCConnectionReconfigurationComplete message to the macro cell.

The embodiments also disclose a method comprising sending, by a macrocell, a configuration message to a wireless communication device, theconfiguration message comprising a configuration of measurementreporting; and performing, by the wireless communication device, ameasurement of one or more indirect network connection nodes forproviding a user plane as well as macro cells, according to configuredsetup of measurement reporting.

The configuration message may for example be an RRC Connection Setupmessage. The configuration message may for example be sent from an eNBto a LIE in response to an RRC Connection Request message that is sentfrom the UE to the eNB.

The method may further comprise sending, by the wireless communicationdevice, a RRC Connection Setup Complete message to the macro cell.

Still further, the method may comprise starting, by the macro cell (e.g.eNB), the provision of control plane to the wireless communicationdevice.

When any event of reporting a measurement is triggered, the wirelesscommunication device may then send respective measurement reports to themacro cell (e.g. eNB).

The embodiments also disclose a method further comprising, selecting anindirect network connection node by the macro cell (or by a nodeconnected to the macro cell) based on the measurement results reportedby the wireless communication device.

Alternatively, an indirect network connection node may be selected bythe wireless communication device based on the measurement results.

The embodiments also disclose a method further comprising sending, bythe macro cell, a second configuration message to the wirelesscommunication device to indicate an attachment of an indirect networkconnection node for provision of a user plane to the wirelesscommunication device.

This second configuration message may for example be an RRCConnectionReconfiguration message. This sending of an secondconfiguration message from the macro cell (e.g. eNB) to the wirelesscommunication device (UE) may by triggered when the macro cell decides,based on the measurement reporting by the wireless communication device,that an indirect network connection node (e.g. a virtual cell/localcell) can provide the wireless communication device with a user plane.

The embodiments also disclose a method further comprising requesting, bythe macro cell, an indirect network connection node to provide thewireless communication device with a user plane.

Upon the macro cell's request to provide the wireless communicationdevice with a user plane, the indirect network connection node may thenstart to provide the wireless communication device with a user plane.

The embodiments also disclose a method further comprising sending, bythe macro cell, a connection release message to the wirelesscommunication device. This connection release message may for example bean RRC Connection Release message.

The embodiments also disclose a method comprising: sending, by a UE, anRRC Connection Request message to an eNB; sending, by the eNB, an RRCConnection Setup message to the UE, the RRC Connection Setup messagecomprising a configuration of UE measurement reporting; sending, by theUE, a RRC Connection Setup Complete message to the eNB; starting, by theeNB, the provision of control plane to the UE; performing, by the UE, ameasurement of virtual cells for user plane as well as macro cells,according to configured setup of measurement reporting; sending, by theUE, a respective measurement report to eNB when an event of reporting ameasurement is triggered; requesting, by the eNB, a virtual cell/localcell to provide the UE with user plane; and starting, by the virtualcell/local cell, to provide the UE with user plane.

Still further, a wireless communication device may have two connectionsfor control signaling to a first and a second base station and may haveto perform measurement and reporting for each link of connection.Although each measurement report of each link can be managed by eachlink separately, measurement reports of both links can be reported usingone of links depending on the link quality, traffic load, or the like.That is to say, in the case that traffic is much loaded on theconnection to the first base station, a measurement report of the linkbetween the wireless communication device and the first base station canbe reported via the connection to the second base station as well as ameasurement report of the link between the wireless communication deviceand the second base station.

In the embodiments described below in more detail it is furtherdescribed an indirect network connection node that is configured toprovide a user plane and/or a control plane to a wireless communicationdevice.

In the embodiments described below in more detail it is furtherdescribed a system comprising a wireless communication device asdescribed above, at least one macro cell, the macro cell beingconfigured to provide a control plane to the wireless communicationdevice, and at least one indirect network connection node, the indirectnetwork connection node being configured to provide a user plane and/ora control plane to the wireless communication device. The system may beconfigured to perform any of the methods described above.

The embodiments described below in more detail focus on efficientoperation using localized dense wireless small cells such as virtualcells/local cells under operation with a separation of the control planeand the user plane. One important aspect when using dense small cells isthe reduction of overhead in measurements related to mobility andunnecessary handover. The embodiment described below in more detailprovide a solution to reduce measurements for cell reselection,including localized dense wireless small cells/local cells in idle mode.Furthermore the embodiments provide a solution for an efficient mobilitymanagement, such as independent configurable measurement reporting tothe eNB and to the virtual cell/local cell.

Provision of the user plane by a virtual cell/local cell depending onRRC Idle and RRC Connected Mode

Embodiments of communication management are shown in the following,assuming usage of a virtual cell/local cell for a provision of a userplane under operation with physical separation between control plane anduser plane.

FIG. 1 schematically discloses an example of a UE operating in idlemode. A UE 10 is initially in RRC Idle mode and doesn't have a RRCconnection. User entity 10 is within the coverage of an eNB 30 which canprovide a direct access to the network (not shown in FIG. 1). Eventhough coverage of a virtual cell/local cell 20 is available for the UE10, the UE 10 performs cell selection/reselection in idle mode measuringonly eNBs (macro cells) according to the conventional procedure. From anetwork point of point view, the most necessary function is mobilitymanagement in RRC Idle mode, so that the network can perform the pagingto UE 10. Here, in RRC Idle mode a macro-based cellselection/reselection procedure is performed, i.e. UE 10 disregardsindirect network nodes such as virtual cell/local cell 20 whenperforming cell selection/reselection. This helps to avoid that the UE10 is forced to perform a lot of measurements including many virtualcells/local cells which might cause undesirable power consumption.

According to the embodiment of FIG. 1 the UE 10 triggers the measurementincluding virtual cells/local cells as well as macro cells in accordancewith its turning into the RRC Connected mode for communication, e.g. inaccordance with a RRC connection establishment procedure (see FIG. 6)which is well known as the procedure which is used to make thetransition from RRC Idle mode to RRC Connected mode. In particular, theUE measurement reporting including intra-frequency/inter-frequencymeasurement for attaching user plane served by a virtual cell/local cellis configured by a RRC Connection Setup message.

FIG. 2 schematically depicts an example of a UE operating in RRC InitialConnected mode. In order to change to RRC Initial Connected mode, the UE10 has received a respective RRC connection setup message during the RRCconnection establishment procedure. eNB 30 now provides the controlplane (C-PL) to UE 10. In particular, the RRC connection setup messagetriggered that the UE 10 performs measurement including virtualcells/local cells as well as macro cells.

FIG. 3 schematically depicts an example of a UE operating in RRCOperational Connected mode. Based on the measurement reports receivedfrom UE 10, the network (e.g. by eNB 30) triggers a provision of userplane from virtual cell/local cell 20 to UE 10. The user entity 10 isnow operational connected to the network by means of eNB 30 and virtualcell/local cell 20. eNB 30 provides the control plane (C-PL) to userentity 10. Virtual cell/local cell 20 provides the user plane (U-PL) touser entity 10.

FIG. 4 shows an embodiment of an RRC Connection Setup message. The RRCConnection Setup message 100 defines “Measurement Objects” 110,“Reporting Configurations” 120, “Measurement Identities” 130, “QuantityConfigurations” 140 and “Measurement Gaps” 150. “Measurement Objects”110 defines the objects on which the UE shall perform the measurements,e.g. frequencies and cells, including intra- and inter-frequencymeasurement object, etc. Intra-frequency and inter-frequency measurementobject can specify individual cells to measure (whitelist), andindividual cells to exclude from measurements (blacklist. Individualcells are referenced by their Physical layer Cell Identities (PCI) inconventional manner. Virtual Cells/local Cells may be identified bytheir Physical layer Cell Identities (PCI) just in the same way as macrocells are identified by their Physical layer Cell Identities (PCI).Here, when a virtual cell/local cell is activated, a PCI of the virtualcell/local cell can be assigned and the PCI may be updated to some ofwhitelists/Neighbour Cell Lists. On the other hand when the virtualcell/local cell is deactivated, this PCI can be released and it may beremoved from whitelist/Neighbour Cell List. This modification ofwhitelist/Neighbour Cell List can be updated to only UEs in connectedmode, since UEs in idle mode can perform macro cell based cellselection/reselection. Furthermore the UE may specify the virtualcell/local cell based on both the PCI of the macro cell which thevirtual cell belongs to and the PCI of the virtual cell so that eachmacro cell can reuse the same PCI for virtual cell(s)/local cell(s)inside coverage of it. Each whitelist/Neighboring Cell List includingvirtual cell(s)/local cell(s) can be provided by each macro cell inhierarchy manner via some SIBs. “Reporting Configurations” 120 definescriteria that are used by a UE to trigger the transmission of ameasurement report and the quantities that the UE includes in thereport. “Measurement Identities” 130 defines respective identifiers thatlink one measurement object with one reporting configuration. Ameasurement identity is used as a reference number in the measurementreport. “Quantity-configurations” 140 defines the measurement quantitiesand associated filtering used for all event evaluation and relatedreporting per Radio Access Technology (RAT). “Measurement gaps” 150defines periods of time that the UE may use to perform measurementswhile in connected mode.

FIG. 5 shows the “Measurement Objects” (110 in FIG. 4) in more detail.Measurement Objects 110 comprises a list of individual measurementobjects. Each measurement object is identified by an object ID 111. Eachobject ID is associated with a specific measurement frequency 113 and aspecific Physical layer Cell Identity (PCI) 115. In the example of FIG.5 “Measurement Objects” comprises three measurement objects. A firstmeasurement object is identified by object ID 1. It relates to aspecific frequency “LTE carrier frequency 1” and to a specific cell withPhysical layer Cell Identity 4. A second measurement object isidentified by object ID 2. It relates to a specific frequency “LTEcarrier frequency 2” and to a specific cell with Physical layer CellIdentity 5. A third measurement object is identified by object ID 3. Itrelates to a specific frequency “UMTS carrier frequency 1” and to aspecific cell with Physical layer Cell Identity 10.

In order to distinguish one RRC state (FIG. 2) from the other RRC state(FIG. 3), the system may define two RRC states which would be for themacro cell and for the virtual cell, respectively. According to thisembodiment, the condition in FIG. 2 is RRC connected mode for the macrocell 30 and RRC idle mode for the virtual cell 20. On the other hand,according to this embodiment, the condition in FIG. 3 is RRC connectedmode for macro cell 30 and RRC connected mode for virtual cell 20. Thatis, a UE may have RRC connections with both, an eNB and a virtual cell,each RRC connection defining its own RRC state.

FIG. 6 schematically shows an example of a procedure to activate theprovision of user plane by a virtual cell. A UE performs cellselection/reselection in idle mode. Prior to starting communication, atS100, the UE sends an RRC Connection Request message to an eNB. Inresponse to this request, at S101, the eNB sends an RRC Connection Setupmessage to the UE. Furthermore, at S101 the UE is configured with UEmeasurement reporting by the eNB. According to the configured setup ofmeasurement reporting, the UE performs a measurement of additionalvirtual cells/local cells for user plane as well as macro cells. Afterthe UE completes any necessary setup based on the RRC Connection Setupmessage, at S102, the UE sends a RRC Connection Setup Complete messageto the eNB. Then, at S103, the eNB starts provision of control plane tothe UE. When any events of reporting the measurement are triggered, theUE, at S104, sends a measurement report to eNB. When the eNB decidesbased on the measurement report that a virtual cell/local cell canprovide the UE with user plane, the eNB, at S105, sends a RRCConnectionReconfiguration message to indicate an attachment of thevirtual cell/local cell for provision of user plane to the UE. After theUE completes any necessary setup based on RRC ConnectionReconfigurationmessage, the UE sends, at S106, a RRC ConnectionReconfigurationCompletemessage to the eNB. When the eNB receives the RRCConnectionReconfigurationComplete message, the eNB, at S107, requests avirtual cell/local cell to provide it with user plane. After the virtualcell/local cell receives the request of provision of user plane, thevirtual cell, at S108, starts the provisioning of user plane to the UE.

FIG. 7 schematically shows an example of a procedure to release theprovision of control plane by an eNB and user plane by a virtual cell.In connected mode an eNB serves control plane to a UE and in this mode avirtual cell (VC)/local cell can serve user plane to the UE and the UEperforms measurement of virtual cells/local cells as well as eNBs. Afterthe UE finishes communication, the network may indicate to the UE tooperate in idle mode for power saving. One possible procedure to makethe UE operate in idle mode, is the use of an RRC Connection Releaseprocedure. According to this embodiment, in the same way as it ispresently done in LTE, the eNB may trigger a UE context release requestto a Mobility Management Entity (MME) and the eNB, at S200, sends a RRCConnection Release message to UE after exchanging the necessary messageamong eNB, MME and S-GW (Serving GateWay). This procedure can betriggered by the eNB in cooperation with the virtual cell/local cell(i.e. the virtual cell/local cell may send some notification to eNB). Inresponse to the RRC Connection Release message, at S201, the eNBreleases the provision of the control plane and the virtual cellreleases the provision of the user plane.

Furthermore in a future network such as 5G, new technology such asSoftware Defined Network (SDN) may be introduced. In this technology afunction of a base station such as eNB and of a relay node, includingvirtual cell/local cell, may be similar to that of a router. In such a5G network scenario, some newly introduced node may handle the role oftriggering the RRC Connection Release procedure.

In accordance with the RRC Connection Release procedure, absolutepriorities of cell reselection can be allocated to RF carriers belongingto both LTE and other Radio Access Technology (RAT) by using broadcastedsystem information. Here, the eNB may remove virtual cells/local cellsfor provision of user plane from “Measurement Objects” in accordancewith the RRC Connection Release procedure so that the UE does not needto perform measurement of virtual cells/local cells as candidates (i.e.whitelist/Neighbour Cell List) for cell reselection. The removal of avirtual cell/local cells from “Measurement Objects” can also be done bya RRC Connection Reconfiguration procedure prior to the RRC ConnectionRelease procedure.

In accordance with the procedures shown in FIG. 6 and FIG. 7, the UE canperform the measurement of virtual cells/local cells for provision ofuser plane only during connected mode.

Sharing of the Control Plane Between an eNB and a Virtual Cell/LocalCell in RRC Connected Mode

In addition to the physical separation of control plane and user plane,a separation of the functions handled by the control plane can also beconsidered, taking into account suitable role assignment to eNB andvirtual cell/local cell.

Since the mobility should be handled on a wider area basis, taking intoaccount reduction of handover and so on, the control plane provided by amacro cell should handle any controls related to mobility management.Although a resource management on the control plane by the macro cellshould be handled by the control plane provided by the macro cell, aresource management on the user plane provided by a virtual cell/localcell may be handled by the virtual cell itself, e.g. when the operationcarrier frequency of the virtual cell/local cell is different from thatof the eNB.

On the other hand, as envisaged with regard to a usage of mmWave andhigh dense small cells in 5G, an operation band of the user plane can bedifferent from that of the control plane. Considering capacityimprovement by usage of high dense small cells and the propagationcharacteristics of mmWave, different performance requirements betweenthe control plane and the user plane are to be expected (i.e. thecontrol plane is required to have a wider coverage than the user plane).

FIG. 8 shows an exemplary embodiment in which a UE is provided with twocontrol planes. According to the embodiment presented here, from ascheduling point of view, although the cross carrier scheduling could beapplied to this operation, it is foreseen that the notification ofscheduling assignment of each link between eNB and UE, or between thevirtual cell/local cell and UE is performed by the eNB or, respectively,the virtual cell/local cell. That is to say, each link has a respectivecontrol plane. At least the control plane by eNB 30 handles controlsrelated to mobility management and the notification of schedulingassignment on the control plane by eNB. Furthermore, as it is taken intoaccount that a decision of handover and attach/detach of user planewould be performed by eNB, the control plane by eNB 30 also handles themeasurement reporting for both eNB 30 and virtual cell/local cell 20, sothat UE 10 can send both measurement report to the eNB 30.

In this embodiment, as it is taken into account that the cell sizes ofthe eNB and the virtual cell/local cell are different from each other,an event trigger for reporting measurement results is configured by eNB30 and the virtual cell/local cell 20 independently. For example, eventdriven reports or periodic reports for eNB 30 can be configured by a RRCConnection Setup message in accordance with the RRC Connection Setupprocedure, and event driven reports or periodic reports for virtualcell/local cell 20 can be configured by a RRC ConnectionReconfigurationmessage in accordance with the RRC ConnectionReconfiguration procedure,respectively.

Another possible solution for measurement reporting is to foresee thatthe measurement of each link between eNB 30 and UE 10 or between virtualcell/local cell 20 and UE 10 is handled by eNB 30 and virtual cell/localcell 20 independently, having a respective control plane over each link.According to this embodiment, even though independent configuration ofmeasurement reporting is performed, since eNB 30 should handle bothdecision of handover of eNB itself and attach/detach of connectionbetween virtual cell/local cell 20 and UE 10, the measurement report onthe link between virtual cell/local cell 20 and UE 10 is sent to eNB 30via the virtual cell/local cell 20 using the backhaul link.

Furthermore, in order to enhance 3GPP Rel-12 D2D (device to device)communication, a UE-NW relay operation is discussed in 3GPP Rel-13.Since the specified PC5 interface for D2D communication is based onbroadcast communication, Hybrid Automatic Repeat reQuest (HARQ) is notsupported for D2D communication. Taking into account that one ofexpected effect of virtual cell/local cell operation will be animprovement of the cell capacity by means of high dense deployment forhot spots, a virtual cell/local cell is expected to support unicastcommunication and HARQ. If this HARQ is managed via control plane byeNB, re-transmission data needs to be transferred over the backhaul linkbetween the virtual cell/local cell and the donor eNB, even though thisre-transmission is caused by a bad link quality between a wirelesscommunication device and the virtual cell/local cell, and consumption ofa lot of radio resources is expected to cause a problem of lack of radioresources. In view of this, it is here foreseen that the HARQ functionis performed within the localized area served by a virtual cell/localcell, and that HARQ on the link between the virtual cell/local cell andthe UE is managed by the control plane provided by the virtualcell/local cell.

FIG. 9 schematically describes an embodiment of an electronic devicethat can be used to implement a wireless communication device that canact as user equipment (UE) in a telecommunication network. The wirelesscommunication device 900 comprises circuitry 901-921 such as a CPU 901as processor. The wireless communication device 900 further comprises amicrophone 910, a loudspeaker 911, and a touchscreen 912 that areconnected to the processor 901. These units 910, 911, 912 act as aman-machine interface and enable a dialogue between a user and thewireless communication device 900. The wireless communication device 900further comprises a WLAN interface 905 and an UMTS/LTE interface 904.These units 904, 905 act as I/O interfaces for data communication withexternal devices such as companion devices, servers, or cloud platforms.The wireless communication device 900 further comprises a camera sensor920 and a GPS sensor 921. These units 920, 921 act as data sources andprovide sensor data. The wireless communication device 900 furthercomprises circuitry such as data storage 902 and data memory 903 (here aRAM). The data memory 903 is arranged to temporarily store or cache dataor computer instructions for processing by processor 901. The datastorage 902 is arranged as a long term storage, e.g. for recordingcomputer instructions or data received from a communication network,e.g. via the UMTS/LTE interface 904.

It should be noted that the description above is only an exampleconfiguration. Alternative configurations may be implemented withadditional or other sensors, storage devices, interfaces or the like.For example, interface 904 may support other radio access technologiesthan the mentioned technologies UMTS and LTE, and components such ascamera sensor 920 and a GPS sensor 921, and the like may be omitted.

An electronic device with components as described in FIG. 9 can also beused to implement an indirect network connection node such as a virtualcell.

Still further also a macro base station can be implemented by anelectronic device such as described with regard to FIG. 9. Just as theelectronic device of FIG. 9 a macro base station comprises one or moreprocessors and memories/storage for implementing control functionalityby means of computer program instructions, and the like. A macro basestation further comprises an air interface (providing e.g. E-UTRAprotocols OFDMA (downlink) and SC-FDMA (uplink)) and network interfaces(implementing for example protocols such as S1-AP, GTP-U, S1-MME, X2-AP,or the like). The present disclosure is not limited to anyparticularities of such interfaces and respective protocols.

It should be recognized that the embodiments describe methods with anexemplary ordering of method steps. The specific ordering of methodsteps is however given for illustrative purposes only and should not beconstrued as binding.

It should be recognized that the division of the mobile communicationdevice (900 in FIG. 9) into units 901 to 921 is only made forillustration purposes and that the present disclosure is not limited toany specific division of functions in specific units. For instance, theprocessor 901 could be implemented by a respective programmed processor,field programmable gate array (FPGA) and the like.

The embodiments describe methods for providing mobile communication.These methods can also be implemented as a computer program causing acomputer and/or a processor (such as processor 901 of FIG. 9), toperform the method, when being carried out on the computer and/orprocessor.

According to the embodiments, the methods may also be implemented by anon-transitory computer-readable recording medium that stores therein acomputer program product, which, when executed by a processor, such asthe processor described above, causes the method described to beperformed.

All units and entities described in this specification and claimed inthe appended claims can, if not stated otherwise, be implemented asintegrated circuit logic, for example on a chip, and functionalityprovided by such units and entities can, if not stated otherwise, beimplemented by software.

In so far as the embodiments of the disclosure described above areimplemented, at least in part, using software-controlled data processingapparatus, it will be appreciated that a computer program providing suchsoftware control and a transmission, storage or other medium by whichsuch a computer program is provided are envisaged as aspects of thepresent disclosure.

Further, it should be recognized that as far as the disclosure refers tocircuitry that is configured to perform a specific function it is alsoenvisaged that the circuitry may be configured to perform the methodsdescribed in the embodiments by means of computing instructions,software, computer programs, and/or the like.

Note that the present technology can also be configured as describedbelow.

(1) A wireless communication device comprising circuitry that isconfigured to measure, in an idle mode, only macro cells, and to startthe measurement of one or more indirect network connection nodes inaccordance with the wireless communication device turning into aconnected mode.

(2) The wireless communication device of (1) in which the circuitry isconfigured to receive/transmit a control plane from/to a macro cell anda user plane from/to one of the indirect network connection nodes.

(3) The wireless communication device of anyone of (1) to (2) in whichthe circuitry is configured to trigger a measurement of virtualcells/local cells in addition to that of macro cells in accordance withan RRC connection establishment.

(4) The wireless communication device of anyone of (1) to (3) in whichthe circuitry is further configured to receive a configuration messageand to perform measurement reporting as defined by the configurationmessage.

(5) The wireless communication device of (4) in which the configurationmessage defines measurement objects, the measurement objects includingintra-frequency measurement objects/inter-frequency measurement objectswhich specify individual cells to measure.

(6) The wireless communication device of (4) in which the configurationmessage defines individual cells that are to be excluded frommeasurements.

(7) The wireless communication device of (4) in which the configurationmessage defines one or more macro cells for a provision of a controlplane and one or more indirect network connection nodes for a provisionof a user plane.

(8) The wireless communication device of anyone of (1) to (7) in whichthe circuitry is further configured to manage connection states incooperation with the network, wherein connection states for a controlplane include an idle and/or a connected state, and the connectionstates for the user plane include at a least a connected state.

(9) The wireless communication device of anyone of (1) to (8) in whichthe circuitry is further configured to configure settings related tomeasurement reporting based on a classification of cell identification.

(10) The wireless communication device of anyone of (1) to (9) in whichthe circuitry is further configured to receive/transmit a control planeprovided by an indirect network connection node and a user plane that isprovided by the indirect network connection node.

(11) The wireless communication device of anyone of (1) to (10) in whichthe circuitry is further configured to receive/transmit a first controlplane provided by an indirect network connection node and a secondcontrol plane that is provided by a macro cell.

(12) The wireless communication device of anyone of (1) to (11) in whichthe control plane is provided by an eNB and in which the control planehandles controls related to mobility management, the schedulingassignment, and/or the measurement reporting for both the eNB and theindirect network connection node.

(13) The wireless communication device of anyone of (1) to (12)comprising circuitry configured to manage event triggers forindependently reporting measurement results to the eNB and/or to theindirect network connection node.

(14) The wireless communication device of anyone of (1) to (13) in whichthe circuitry is further configured to perform a HARQ function withinthe localized area served by the indirect network connection node.

(15) The wireless communication device of (14) in which the circuitry isfurther configured to manage a HARQ on the link between the indirectnetwork connection node and the wireless communication device by acontrol plane provided by the indirect network connection node.

(16) A method comprising:

-   -   sending, by a macro cell, a configuration message to a wireless        communication device, the configuration message comprising a        configuration of measurement reporting; and    -   performing, by the wireless communication device, a measurement        of one or more indirect network connection nodes for providing a        user plane as well as macro cells, according to configured setup        of measurement reporting.

(17) The method of (16), further comprising, selecting an indirectnetwork connection node by the macro cell based on the measurementresults reported by the wireless communication device.

(18) The method of (16) or (17), further comprising sending, by themacro cell, a second configuration message to the wireless communicationdevice to indicate an attachment of an indirect network connection nodefor provision of a user plane to the wireless communication device.

(19) The method of anyone of (16) to (18), further comprisingrequesting, by the macro cell, an indirect network connection node toprovide the wireless communication device with a user plane.

(20) The method of anyone of (16) to (19) further comprising sending, bythe macro cell, a connection release message to the wirelesscommunication device.

(21) A method comprising:

-   -   sending, by a UE, an RRC Connection Request message to an eNB;    -   sending, by the eNB, an RRC Connection Setup message to the UE,        the RRC Connection Setup message comprising a configuration of        UE measurement reporting;    -   sending, by the UE, a RRC Connection Setup Complete message to        the eNB;    -   starting, by the eNB, the provision of control plane to the UE;    -   performing, by the UE, a measurement of virtual cells/local        cells for user plane as well as macro cells, according to        configured setup of measurement reporting;    -   sending, by the UE, a respective measurement report to eNB when        an event of reporting a measurement is triggered;    -   requesting, by the eNB, a virtual cell/local cell to provide the        UE with a user plane; and    -   starting, by the virtual cell/local cell, to provide the UE with        a user plane.

(22) An indirect network connection node comprising circuitry configuredto provide a user plane and/or a control plane to a wirelesscommunication device as defined in (1) to (15).

(23) A system comprising

-   -   a wireless communication device as defined in (1) to (15);    -   at least one macro cell, the macro cell being configured to        provide a control plane to the wireless communication device;        and    -   at least one indirect network connection node, the indirect        network connection node being configured to provide a user plane        and/or a control plane to the wireless communication device.

(24) A wireless communication method comprising:

-   -   a wireless communication device establishing a first connection        to exchange control signaling with a first base station,    -   wherein the first base station is selected among candidate base        stations which are configured prior to the establishment of the        first connection, and    -   a second base station which the first base station can control        via the first connection, isn't included in the candidate base        stations prior to the establishment of the first connection,    -   the first base station configuring the wireless communication        device with a settings related to measurement of the first base        station and one or a plurality of the second base station via        dedicated control signaling over the first connection or        broadcasted signaling, and indicating a second connection        between the wireless communication device and the second base        station selected based on measurement results performed by the        wireless communication device,    -   wherein the wireless communication device exchanging data with a        network by the second connection via the second base station.

(25) The wireless communication method of (24) further comprising:

-   -   the candidate base stations which are configured prior to the        establishment of the first connection, are categorized into a        first and a second candidate base stations,    -   wherein the wireless communication device selects the first base        station among the first candidate base stations, and    -   the wireless communication device selects the second base        station among the first and the second candidate base stations.

(26) The wireless communication method according to (24) or (25) furthercomprising the second base station being selected by the first basestation or a node connected to the first base station based on themeasurement results reported by the wireless communication device.

(27) The wireless communication method according to anyone of (24) or(26) further comprising: the second base station being selected by thewireless communication based on the measurement results.

(28) The wireless communication method according to anyone of (24) or(27) further comprising: the wireless communication device managingconnection states in cooperation with the network, wherein theconnection states for the first connection including idle or connectedstate and the connection states for the second connection including atleast connected state.

(29) The wireless communication method according to anyone of (24) or(28) further comprising: the settings related to measurement reportingbeing configured based on a classification of cell identification.

(30) The wireless communication method according to anyone of (24) or(29) further comprising: the classification being classified based on atleast one of size of cell coverage, maximum transmission power, numberof equipped antenna, operating frequency band and bandwidth.

(31) The wireless communication method according to anyone of (24) or(30) further comprising: the second connection being divided into aconnection for control signaling and a connection for data communicationin logical or physical manner.

(32) The wireless communication method according to anyone of (24) or(31) further comprising:

-   -   the second base station configuring the settings of measurement        reporting of the second base station in accordance with        establishment of the second connection, and    -   a measurement report on the link between the wireless        communication device and the second base station being sent to        the second base station using the second connection.

(33) The wireless communication method according to anyone of (24) or(32) further comprising: the connection for control signaling amongconnections being divided the second connection into, is used forsending the measurement report on the link between the wirelesscommunication device and the second base station.

1: A wireless communication device, comprising: circuitry configured tomeasure, in an idle mode, only macro cells, and start the measurement ofone or more indirect network connection nodes in accordance with thewireless communication device turning into a connected mode, and performreceiving and transmitting a first control plane provided by an indirectnetwork connection node and a second control plane that is provided by amacro cell. 2: The wireless communication device of claim 1, wherein thecircuitry is configured to perform one or more of receiving a controlplane from and transmitting a control plane to a macro cell andreceiving a user plane from and transmitting a user plane to one of theindirect network connection nodes. 3: The wireless communication deviceof claim 1, wherein the circuitry is configured to trigger a measurementof virtual cells/local cells in addition to that of macro cells inaccordance with an RRC connection establishment. 4: The wirelesscommunication device of claim 1, wherein the circuitry is furtherconfigured to receive a configuration message and perform measurementreporting as defined by the configuration message. 5: A methodcomprising: sending, by a macro cell, a configuration message to awireless communication device, the configuration message comprising aconfiguration of measurement reporting; performing, by the wirelesscommunication device, a measurement of one or more indirect networkconnection nodes for providing a user plane as well as macro cells,according to configured setup of measurement reporting; and performing,by the wireless communication device, receiving and transmitting a firstcontrol plane provided by an indirect network connection node and asecond control plane that is provided by a macro cell. 6: The method ofclaim 5, further comprising: selecting an indirect network connectionnode by the macro cell based on the measurement results reported by thewireless communication device. 7: The method of claim 5, furthercomprising: sending, by the macro cell, a second configuration messageto the wireless communication device to indicate an attachment of anindirect network connection node for provision of a user plane to thewireless communication device. 8: The method of claim 5, furthercomprising: requesting, by the macro cell, an indirect networkconnection node to provide the wireless communication device with a userplane. 9: The method of claim 5, further comprising: sending, by themacro cell, a connection release message to the wireless communicationdevice. 10: The wireless communication device of claim 4, wherein theconfiguration message defines one or more macro cells for a provision ofa control plane and one or more indirect network connection nodes for aprovision of a user plane. 11: The wireless communication device ofclaim 1, wherein the circuitry is further configured to manageconnection states in cooperation with the network, wherein connectionstates for a control plane include one or more of an idle and aconnected state, and the connection states for the user plane include atleast a connected state. 12: The wireless communication device of claim1, wherein the circuitry is further configured to configure settingsrelated to measurement reporting based on a classification of cellidentification. 13: A system, comprising: a wireless communicationdevice, wherein the wireless communication device includes circuitryconfigured to measure, in an idle mode, only macro cells, and start themeasurement of one or more indirect network connection nodes inaccordance with the wireless communication device turning into aconnected mode, and perform receiving and transmitting a first controlplane provided by an indirect network connection node and a secondcontrol plane that is provided by a macro cell. 14: The system of claim13, wherein the circuitry is configured to perform one or more ofreceiving a control plane from and transmitting a control plane to amacro cell and receiving a user plane from and transmitting a user planeto one of the indirect network connection nodes. 15: The system of claim13, wherein the circuitry is configured to trigger a measurement ofvirtual cells/local cells in addition to that of macro cells inaccordance with an RRC connection establishment. 16: The system of claim13, wherein the circuitry is further configured to receive aconfiguration message and perform measurement reporting as defined bythe configuration message. 17: The system of claim 16, wherein theconfiguration message defines one or more macro cells for a provision ofa control plane and one or more indirect network connection nodes for aprovision of a user plane. 18: The system of claim 13, wherein thecircuitry is further configured to manage connection states incooperation with the network, wherein connection states for a controlplane include one or more of an idle and a connected state, and theconnection states for the user plane include at least a connected state.19: The system of claim 13, wherein the circuitry is further configuredto configure settings related to measurement reporting based on aclassification of cell identification. 20: The system of claim 13,wherein the control plane is provided by an eNB and the control planehandles one or more of controls related to mobility management, thescheduling assignment, and the measurement reporting for both the eNBand the indirect network connection node.